Method for cloud-based access control policy management

ABSTRACT

A Web-based management server includes an ACP manager to manage access control rules (ACRs) and access control policies (ACPs). The ACRs and ACPs are configured by an administrator via a Web interface of the management server. The ACP manager is to transmit over the Internet the ACPs and the ACRs to network access devices (NADs) to allow the NADs to apply the ACPs to their respective network client devices (NCDs) based on the ACRs, where the NADs are managed by the management server over the Internet. Each of the NADs operates as one of a router, a network switch, and an access point. The ACP manager is to periodically update the ACRs and ACPs stored in the NADs, including receiving an update from one NAD and broadcasting the update to a remainder of the NADs.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/011,517, filed on Aug. 27, 2013, which claims the benefit of U.S.Provisional Patent Application No. 61/695,995, filed Aug. 31, 2012,which are incorporated by reference herein in their entirety.

FIELD OF THE INVENTION

Embodiments of the present invention relate generally to networking.More particularly, embodiments of the invention relate to managingaccess control policies over the Internet.

BACKGROUND

A physical local area network (LAN) may include numerous network accessdevices (e.g., routers, switches, wireless access points, etc.) thatcommunicate with one another (either directly or indirectly) to providecomputing device(s) (e.g., laptop, smartphone, etc.) access to a widearea network (WAN). Thus, a network access device (NAD) is a piece ofnetworking equipment, including hardware and software, whichcommunicatively interconnects other equipment on the LAN (e.g., othernetwork elements, computing devices). The WAN can include, for example,the Internet, where communication with the WAN is through an interfacesuch as T1, T3, cable, Digital Subscriber Line (DSL), wireless (e.g.,mobile cell tower), or the like.

The one or more of the network access devices within the LAN that aredirectly coupled to the WAN or directly coupled to an interface device(e.g., a DSL modem) act as a gateway node for the LAN (a gateway to theWAN) for the other network access devices and network computing devicesin the LAN. Network access devices that rely on (communicate with) oneor more other network access devices to reach the WAN act asintermediate nodes of the LAN.

Generally the access control rules must either be configured manually oneach network access device (e.g. individual access points or switches),or if a controller based system is used then the rules are configured onthe controller. Configuring access control rules manually on eachnetwork access device is cumbersome, time-consuming and error-prone.Using a controller-based system simplifies this somewhat, butcontrollers are expensive and can only support a limited number ofnetwork access devices each, after which additional controllers must bedeployed and access control rules synchronized between them. Also, ifmany network access devices are located in geographically disparatelocations, synchronizing the access control rules can be confusing.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are illustrated by way of example and notlimitation in the figures of the accompanying drawings in which likereferences indicate similar elements.

FIG. 1 is a block diagram illustrating a cloud managed network systemaccording to one embodiment of the invention.

FIG. 2 is a block diagram illustrating a data structure representingaccess control rules and access control policies according to oneembodiment of the invention.

FIG. 3 is a block diagram illustrating a data structure representing anaccess control rule log according to one embodiment of the invention.

FIG. 4 is a flow diagram illustrating a method for managing accesscontrol rules and policies according to one embodiment of the invention.

FIG. 5 is a flow diagram illustrating a method for managing accesscontrol rules and policies according to another embodiment of theinvention.

FIG. 6 is a flow diagram illustrating a method for managing accesscontrol rules and policies according to another embodiment of theinvention.

FIGS. 7A and 7B are block diagrams illustrating a cloud managed networkconfiguration according to certain embodiments of the invention.

FIG. 8 is a block diagram illustrating a network configuration inaccordance with another embodiment of the invention.

DETAILED DESCRIPTION

Various embodiments and aspects of the inventions will be described withreference to details discussed below, and the accompanying drawings willillustrate the various embodiments. The following description anddrawings are illustrative of the invention and are not to be construedas limiting the invention. Numerous specific details are described toprovide a thorough understanding of various embodiments of the presentinvention. However, in certain instances, well-known or conventionaldetails are not described in order to provide a concise discussion ofembodiments of the present inventions.

Reference in the specification to “one embodiment” or “an embodiment”means that a particular feature, structure, or characteristic describedin conjunction with the embodiment can be included in at least oneembodiment of the invention. The appearances of the phrase “in oneembodiment” in various places in the specification do not necessarilyall refer to the same embodiment.

Techniques for managing access control rules (ACRs) and/or accesscontrol policies (ACPs) in a centralized manner are described herein.According to some embodiments, a cloud-based system is provided forspecifying access control rules for a large number of specific networkclient devices (NCDs) that are using a computer network (either wirelessor wired). The system is designed to function with large numbers ofclient devices, authorized for varying and potentially long periods oftime, and even if the network access devices (NADs) (e.g., routers,wireless access points, network switches or firewalls, etc) are numerousand spread out over a large geographic area.

According to one embodiment, a cloud-based management server is used tostore a set of ACRs for a large number of distinct NCDs, also referredto as networked computing devices, in a central location. It furtherprovides an efficient mechanism for synchronizing the ACRs and/or ACPsbetween the central location and a large number of NADs which will beproviding network connectivity and enforcing the access control rulesfor those NCDs. In one embodiment, each ACR specifies one or more ACPs,and optionally an expiration time, for a specific NCD (identified byhardware media access control or MAC address for example). An ACP caninclude a number of access parameters, including bandwidth limits andtraffic shaping rules, virtual LAN (VLAN) assignment, firewall rules,whether a captive portal should be applied to that device, etc.

According to one embodiment, the ACRs are stored centrally as atime-ordered log of additions and deletions of individual ACRs. Each ACRlog entry includes a numerical version that increases over time. NADsperiodically query the central management server by sending the versionof the last log entry that the NAD received, and the central managementserver replies with any additional log entries that have been recordedsince then. In this way, each network access device is kept up-to-datewith the latest ACRs in an efficient manner. A software process runsperiodically on the central management server to perform a house-keepingprocess on the log. In one embodiment, the process re-inserts any old(based on a configurable time period) unexpired ACR entries into thefront of the log. This ensures that the full set of all active ACRs iscontained in the recent portion of the log, and older portions can beperiodically discarded.

FIG. 1 is a block diagram illustrating a cloud managed network systemaccording to one embodiment of the invention. Referring to FIG. 1,system 100 includes, but is not limited to, various network accessdevices (NADs) 102-103 (which may be wired and/or wireless) managed by amanagement server (MS) 101 over WAN 104. Management server 101 may be aWeb or cloud server, or a cluster of servers, running on serverhardware. Each of network access devices 102-103 is associated with aLAN such as LANs 105-106. Network 104 may be the Internet. Networkaccess devices 102-103 may operate as a gateway device, an access point(AP), a network switch, or a combination thereof to LANs 105-106,respectively, where various client devices 108-109 can becommunicatively coupled to LANs 105-106. According to one embodiment, anetwork access device may be a gateway device interfacing a LAN to WAN104 and performs network address translation (NAT) for its clients,which may be network client devices 108-109 or other network accessdevices. A network client device may be any kind of networked computingdevices, such as laptops, desktops, tablets, mobile phones, personaldigital assistants (PDAs), media players, gaming devices, etc.

Referring to FIG. 1, in this example, it is assumed that network accessdevices 102-103 are owned by the same organization and administrated bya network administrator 107 associated with the organization. Also notethat for the purpose of illustration, although network access device 103is not shown with details therein, network access device 103 has thesame or similar architecture as network access device 102. For thepurpose of illustration, only two network access devices are shown, butadditional network access devices may be coupled to network 104 andmanaged by management server 101. Also note that management server 101may manage network access devices for multiple organizations managed bydifferent administrators. For example, network access device 102 may beassociated with a first enterprise that is separate from a secondenterprise associated with network access device 103.

According to one embodiment, management server 101 includes a managementmodule 110 for managing network access devices 102-103. In oneembodiment, each of network access devices 102-103 maintains apersistent tunnel (e.g., a secure communications channel) withmanagement server 101 for exchanging network management messages (alsoreferred to as an mTunnel). When a network access device such as NAD 102boots up, NAD 102 connects and logs onto management server 101 andmanagement server 101 authenticates NAD 102. The hardware identifiersuch as a serial number of NAD 102 is stored in NAD information database111. In addition, NAD 102 may also be assigned with a network identifierfor the purpose of logically grouping NAD 102 with some other NADs suchas NAD 103. Thus, multiple NADs may be associated with the same networkidentifier. Management server 101 further includes a configurationinterface 112, such as a Web interface, to allow administrator 107 tolog into management server 101 to enter configuration information forconfiguring NADs 102-103. For example, administrator 107 may specifyminimum configuration parameters and management module 110 of managementserver 101 automatically compiles other related configurationinformation without requiring the administrator 107 to enter thedetailed configuration information.

According to one embodiment, management server 101 includes an accesscontrol policy (ACP) manager 113 to manage ACPs 114 and access controlrules (ACRs) 115, which may be configured by administrator 107 viaconfiguration interface 112. ACPs 114 and ACRs 115 are used to controlaccess of client devices 108-109. ACPs 114 refer to a set of predefinedpolicies and ACRs 115 refer to a set of rules specifying how ACPs 114should be applied. An ACR may itself be an ACP. ACPs 14 and ACRs 115 maybe implemented as a single entity. According to one embodiment, ACPmanager transmits ACPs 114 and ACRs 115 to each of network accessdevices 102-103 over the Internet and the transmitted ACPs and ACRs arestored in the network access devices 102-103, for example, as ACPs 117and ACRs 118, and managed by an access control module (ACM) such as ACM116.

For example, when network access device 102 boots and connects tomanagement server 101, management server 101 authenticates networkaccess device 102. An mTunnel is created between management server 101and network access device 102. ACPs 114 and ACRs 115 are then downloadedfrom management server 101 to network access device 102 via the mTunneland stored in network access device 102 as ACPs 117 and ACRs 118. When aclient device such as client device 108 is associated with networkaccess device 102, access control module 116 controls the access ofclient device 108 by enforcing ACPs 117 and ACPs 118.

If there is any update concerning ACPs 117 and/or ACRs 118, accesscontrol module 116 transmits the update to management server 101. Inresponse, management server 101 broadcasts the update to other remainingnetwork access devices associated with the same organization, such asnetwork access device 103. For example, when client device 108 connectswith network access device 102 requesting entering LAN 105 in order toaccess the Internet 104, network access device 102 may examine thecorresponding ACRs and/or ACPs to control the access of client device108. In some situations, the ACRs/ACPs associated with client device 108may indicate that the authentication of client device 108 may beperformed via a remote captive portal. As result, network access device102 may redirect the request to the captive portal for authentication.Upon receiving a successful authentication signal, network access device102 may update ACPs 117 and/or ACPs 118 to include informationindicating that client device 108 has been successfully authenticated.Such an update is then transmitted (e.g., pushed by network accessdevice 102 or polled by management server 101) to management server 101and management server 101 broadcasts the update to remaining networkaccess devices such as network access device 103. As a result, bothnetwork access devices 102-103 have the same set of ACPs and ACRs.

According to another embodiment, NADs 102-103 do not need to push ACRsup to management server 101; rather, management server 101 pushes downthe ACRs to NADs 102-103. In one embodiment, a remote captive portal isimplemented with the MS 101. So when a NAD device has authenticated withthe captive portal, the captive portal component notifies the NADimmediately (so that the NAD can let the device online), and it simplyupdates the ACRs in the MS directly, at which point the ACRs aretransmitted to all the other NADs.

Subsequently, referring back to FIG. 1, when client device 108 roamsfrom network access device 102 to network access device 103, networkaccess device 103 can use the same ACPs/ACRs to control the access ofclient device 108. In this example, since the updated ACRs/ACPs storedwithin network access device 103 include information indicating thatclient device 108 has been previously authenticated (e.g., via networkaccess device 102), network access device 103 does not need to redirectthe request to a remote captive portal for authentication again.

According to one embodiment, each of the ACRs 115 specifies one or moreaccess policies or links to one or more of ACPs 114 for a specificnetwork client device (for example, identified by its hardware MACaddress) and an optional expiration time. As mentioned above, an accesspolicy can include a number of parameters including bandwidth limits andtraffic shaping rules, VLAN assignment, firewall rules, whether acaptive portal should be applied to that device, etc. When storing anACR, the specific rules of the policy can either be explicitly stated inthe ACR, or the ACR can refer to the identifying number of a pre-definedACP 115 that is already stored elsewhere in the system, as shown in FIG.2.

In one embodiment, an example ACR that explicitly specifies an ACP canbe defined as follows:

-   -   MAC address: 00:11:22:33:44:55    -   Expiration: Apr. 20, 2012 23:20:42    -   Policy:    -   Download Bandwidth: 2 Mbps    -   Upload Bandwidth: 1 Mbps    -   VLAN ID: 100    -   Firewall: block TCP port 80

An example ACR that refers to a pre-defined ACP may be defined asfollows:

-   -   MAC address: 00:11:22:33:44:55    -   Expiration: (Never expires)    -   Policy: policy_id 105

Referring to FIG. 2, as an example, an ACR is associated with a versionnumber identifying a version of the ACR. An ACR may be configured basedon a network identifier of a network access device. Alternatively, anACR may be configured based on a network identifier of one or morenetwork access devices, rather than applying only to a specific clientdevice. For example, a network access device may be associated with anetwork segment (e.g., a particular department such as financedepartment of a corporation) that only people in certain roles canaccess. Under such a circumstance, a single ACR/ACP may be utilized tocontrol access of any client devices currently associated with thatparticular network access device. According to another embodiment,wireless client devices associated with different SSIDs may be assignedwith different ACRs/ACPs. For example, all client devices associatedwith network access devices with the same network identifier may haveapplied with the same default ACR/ACP. Within the common ACR, there maybe some rules which are exceptions for different SSIDs that may overridethe default rules. An enterprise company may have multiple networkidentifiers and a network identifier may be associated with multipleSSIDs. Other configurations may also be implemented.

Referring back to FIG. 1, according to one embodiment, management server101 maintains a data structure, such as, for example, an ACR log 120, tokeep track of updates or changes of ACRs 114 and/or ACPs 115. The ACRsare stored centrally as a time-ordered log of additions and deletions ofindividual ACRs. Each ACR log entry includes a numerical version thatincreases over time. A convenient implementation of the version is touse a timestamp when that log entry was added, however any numericalvalue that is strictly increasing over time will suffice. An example ofan ACR log 120 is shown in FIG. 3. Referring to FIG. 3, device00:00:01:02:03:05 is assigned to policy_id 105, and 00:00:01:02:03:06 isassigned to policy_id 110; device 00:00:01:02:03:04 had a policy addedand then removed, so its policy is no longer active.

Management server 101 keeps NADs 102-103 up-to-date by periodicallysending any ACRs that have been recorded in the log since the lastupdate they received. In one embodiment, NADs 102-103 periodically querymanagement server 101, sending the version of the log entry that theylast received. Management server 101 replies by sending any ACR entriesfrom the log that were inserted after the version the NAD reportshaving. In another embodiment, management server 101 periodicallyqueries each of the NADs 102-103. The NAD replies with the versionnumber of the last log entry it received, and management server 101 thenreplies with any additional new entries that it has recorded.

If a new NAD is added to the system, it will initially report a versionof zero since it has no ACRs yet, and management server 101 will need toreply with all of the current ACRs. In order to keep this lookupefficient and in order to keep the log from growing without bound,according to one embodiment, a software process runs periodically onmanagement server 101 and re-inserts or copies any old (based on aconfigurable time period) unexpired ACR entries into the front of thelog, and then deletes all old entries. This house-keeping (i.e., garbagecollection) process ensures that the full set of all active ACRs iscontained in the recent portion of the log, and that the size of the logdoes not grow without bound.

Note that a variety of garbage collection methods can be utilized hereinfor such purposes, such as, for example, a mark-and-sweep method. Amark-and-sweep garbage collector maintains a bit (or two) with eachobject (e.g., an ACR entry) to record whether it is white or black(e.g., invalid or valid, where a deleted ACR is an invalid entry); thegrey set is either maintained as a separate list (such as the processstack) or using another bit. As the reference tree is traversed during acollection cycle (the “mark” phase), these bits are manipulated by thecollector to reflect the current state. A final “sweep” of the memoryareas then frees white objects (e.g., invalid entries), for example, bymoving or copying the valid entries with old timestamps (e.g., oldversions) to the top of the queue or buffer, with new timestamps.

According to another embodiment, the entire log is played forward onceto build the final ACR state as of the current time. To accomplish that,ACR entries are added or removed based on the records in the log, andany ACR whose expiration date is now in the past is skipped entirely.This provides a set of ACR entries that are still valid (have neitherexpired nor been explicitly deleted/removed), referred to as the CurrentValid Rules (CVR). The oldest portion of the log (e.g. the oldest oneday's worth of entries, or however much one wants to clean) is playedforward again. Any ACR entry that is in the CVR set is re-inserted atthe front of the log. The oldest portion of the log (whichever portionreinserted) can now be discarded. This has the effect of implicitlydeleting any entries at the back of the log that were no longer valid;we did not re-insert them, and then we deleted all entries. Note that itis not necessary to communicate any of this to the NADs, because theyalready have all the relevant information: ACRs that have expired willalready be dropped by the NADs, and ACRs that were explicitly deletedwill already be deleted on the NADs too. This just prevents us frombroadcasting stale ACRs to new NADs that join the network, and keeps thesize of the log manageable.

Such a garbage collection process may be performed by the managementserver and the management server broadcasts the updated ACRs to thenetwork access devices with a newer version. Alternatively, such agarbage process may be performed by the network access devices, in whicheach of the network access devices maintains an ACR log. For example,the management server may send a command, via a respective persistentmTunnel using a variety of tunneling protocols (e.g., UDP/IP orUDP/HTTP), to network access devices indicating which of the entries arenot invalid (e.g., deleted) to allow the network access devices toremove the invalid entry or entries from its ACR log.

According to some embodiments, ACRs that apply to multiple NCDs can beimplemented by allowing wildcards or ranges of values in the MAC addressfield (e.g., a prefix portion of the MAC) of the ACRs. Multiple layersof policies are possible by including a “priority” for each ACR entry(e.g., a specific rule or exception overriding a default or base rule).This would allow an administrator to specify a default policy for alldevices, for example, and to override that default policy (e.g., policyassociated with a particular network identifier) with a different policyfor specific devices (e.g., specific policies for different SSIDs), byallowing the highest priority policy to take precedence. In a systemwhere multiple logical networks are hosted on the same managementserver, a single ACR log can be used for the whole system by addingappropriate identifier fields to the log. For example, a managementserver might handle functionality for multiple separate networks withseparate rules, in which case a network identifier field could be addedto the ACR log format. Similarly, a wireless network might havedifferent SSIDs which act as different virtual networks with separateaccess control policies, in which case an SSID identifier field could beadded. To improve transmission efficiency of sending ACRs to devices,according to one embodiment, a compact binary format such as GoogleProtocol Buffers or Apache Thrift can be used to send the updates. Toincrease overall system efficiency, NADs can periodically store thecurrent ACR state to local persistent storage. This will make it so thatif their runtime state is lost (e.g. if the device loses power andreboots), they will not need to re-fetch the entire list of ACRs fromthe central server. Instead, they can recover the last known ACR statefrom its local storage after reboot, particularly, if the last knownACRs were updated within a predetermined period of time (e.g., stillfresh or valid). In addition to an administrator configuring ACRs andACPs, according to some embodiments, ACRs can be added automatically bysoftware, e.g. in the case where a user authenticates themselves viacaptive portal; in this case an ACR will be added for that user's NCDwithout direct administrator intervention.

FIG. 4 is a flow diagram illustrating a method for managing accesscontrol rules and policies according to one embodiment of the invention.Method 400 may be performed by management server 101 of FIG. 1, wherethe method may be performed by processing logic that may includesoftware, hardware, or a combination thereof. Referring to FIG. 4, atblock 401, a Web interface is provided at a management server to allowan administrator to configure a set of ACRs and/or ACPs for clientdevices. At block 402, the ACRs and ACPs are then stored in a persistentstorage of the management server. At block 403, the ACRs and ACPs aretransmitted from the management server to multiple network accessdevices that are associated with the same enterprise company. Thenetwork access devices enforce the ACRs and ACPs to control access ofthe associated network client devices. At block 404, the managementserver periodically transmits updates of the ACRs and ACPs to thenetwork access devices over the Internet.

FIG. 5 is a flow diagram illustrating a method for managing accesscontrol rules and policies according to another embodiment of theinvention. Method 500 may be performed by management server 101 of FIG.1, where the method may be performed by processing logic that mayinclude software, hardware, or a combination thereof. Referring to FIG.5, at block 501, a remote version number of ACRs and/or ACPs is receivedby a management server via its Web interface from a network accessdevice over the Internet. At block 502, a local version number of theACRs and/or ACPs is compared with the remote version number. If thelocal version number is greater than the remote version number, at block503, at least delta difference between two versions of the ACRs and/orACPs is transmitted to the network access device replacing the existingversion therein.

FIG. 6 is a flow diagram illustrating a method for managing accesscontrol rules and policies according to another embodiment of theinvention. Method 600 may be performed by a network access device suchas network access devices 102-103 of FIG. 1, where the method may beperformed by processing logic that may include software, hardware, or acombination thereof. Referring to FIG. 6, at block 601, a NAD receivesACRs/ACPs from a management server over the Internet, where themanagement server manages multiple network access devices associatedwith one or more enterprises. At block 602, the ACRs/ACPs are thenstored and enforced by the network access device against its networkclient devices. At block 603, the NAD periodically transmits a versionnumber to the management server representing the current version of theACRs/ACPs currently stored within the network access device. At block604, an update of the ACRs/ACPs is received from the management serverand the update is populated within the network access device at block605.

FIG. 7A is a block diagram illustrating a cloud managed network systemaccording to one embodiment of the invention. System 1000A may beimplemented as part of any of the network systems described above, suchas system 100 of FIG. 1. Referring to FIG. 7A, system 1000A includes,but is not limited to, various network access devices (NADs) 1002-1003managed by a management server 1001 over WAN 1004. Management server1001 may be a Web or cloud server, or a cluster of servers, running onserver hardware. Each of network access devices 1002-1003 may beassociated with a LAN such as LANs 1005-1006. A LAN herein may alsorefer to a sub-network or network segment (e.g., subnet or a virtual LAN(VLAN)) of a larger LAN (e.g., Intranet). Network 1004 may be theInternet. Any of network access devices 1002-1003 may operate as agateway device (e.g., routers 1016 and 1019), an access point (AP)(e.g., APs 1017 and 1020), a network switch (e.g., switches 1015 and1018), or a combination thereof to LANs 105-106, wired or wireless,where various network client devices (NCDs) 1008-1009 can becommunicatively coupled to LANs 105-106.

According to one embodiment, a network access device may represent agateway device interfacing a LAN to WAN 1004 and performs networkaddress translation (NAT) for its clients, which may be client devices1008-1009 or other network access devices. A network access device maybe configured behind another network access device. For example, anuplink of an access point may be coupled to a downlink of a gatewaydevice. Alternatively, an uplink of a network switch may be coupled to adownlink of a gateway device or an access point, etc. A network accessdevice may be an integrated device integrating two or more of thesefunctionalities (e.g., router/gateway, access point, and/or networkswitch), wired and/or wireless.

Referring back to FIG. 7A, in one embodiment, management server 1001works for both single and multi-tenant installations, meaning thatmultiple organizations with different network administrators may havenetwork access devices managed by the same management server, andnetwork configuration or management can be performed using the samemanagement server, but are firewalled off from each other and do nothave access to each other's network configurations. In this example,network access devices 1002 and network access devices 1003 may beassociated with or owned by the different organizations andadministrated by different network administrators 1007A and 1007Bassociated with the organizations. Some of network access devices 1002may communicate with each other to form a local mesh network, while someof network access devices 1003 may communicate with each other to formanother local mesh network.

According to one embodiment, management server 1001 includes amanagement module 1010 and a configuration module 1011 to manage and toconfigure network access devices 1002-1003 and to generate managementserver configuration information for each of network access devices1002-1003, which may be stored in configuration information database1013. In one embodiment, management server 1001 provides a userinterface 1014 such as a Web interface to allow a network administratorsuch as administrators 1007A and 1007B to create and log into an accountassociated with an organization to which the network access devices 1002or network access devices 1003 belong.

The management server 1001 further includes a NAD information database1012, including information regarding the network access devices1002-1003. In one embodiment, the NAD information database 1012 includesa serial number and a mechanism to authenticate the network accessdevice's identity (e.g., the public key of a private public key pair,the private key of which was embedded or stored in the network accessdevice during the manufacturing). NAD information database 1012 may bepopulated different ways in different embodiments (e.g., populated bythe seller of the network access devices, populated by the networkadministrator). In embodiments in which this information is populated bythe seller, different embodiments may associate the informationregarding network access devices 1002-1003 in the router informationdatabase with the user account in different ways (example, networkadministrators 1007A and 1007B may provide an order number (or invoicenumber) associated with a purchase of network access devices 1002 or1003).

According to one embodiment, when a network access device is powered upand attempts entering network 1004, the network access device attemptsto contact management server 1001. In one embodiment, certain deviceinformation such as an IP address and domain name service (DNS) name ofmanagement server 1001 is stored in the network access device when it ismanufactured. In one embodiment, when the network access device ispowered up, the network access device performs any self configurationprocesses including obtaining an IP address for itself from a dynamichost configuration protocol (DHCP) facility (which address may be apublic IP address, or may be a private IP address if there is a deviceperforming NAT between the router and the WAN (that is to say, thenetwork access device is behind a device performing NAT)). The networkaccess device then accesses management server 1001 based on the server'sIP address and authenticates itself (e.g., signing a message (e.g.,including the serial number of the network access device) using aprivate key associated (and/or stored) with the network access device,such that management server 1001 can authenticate the network accessdevice using the associated public key (stored in NAD informationdatabase 1012) maintained by management server 1001).

In one embodiment, each of network access devices 102-103 creates one ormore secure communication channels (e.g., a control tunnel) with server1001 using the keys downloaded from management server 101 to exchangecontrol traffic such as management messages or notification, operatingstatus of the network access device, etc. Such a tunnel for networkmanagement purposes is referred to herein as an mTunnel. In thisexample, network access devices 1002 maintain at least one mTunnel 1021with management server 1001 and network access devices 1003 maintain atleast one mTunnel 1022 with management server 1001. In one embodiment,each of network access devices 1002 may maintain a persistent mTunnelwith management server 1001. Alternatively, only the network accessdevice operating as a gateway device maintains an mTunnel withmanagement server 1001, while other network access devices behind thegateway device communicate with the gateway device to share the samemTunnel. Typically, a network access device operating as a gatewayperforms network address translation (NAT) for its clients, which may bea network client device or another network access device.

In one embodiment, once a network access device has been successfullyauthenticated by server 1001, the network access device downloadsconfiguration information and stores it in a storage device within thenetwork access device. This download may take place over a securesession layer (SSL)-encrypted session and/or the management server mayencrypt the data using the public key corresponding to the private key.This secure channel may also be used to receive subsequent configurationupdates from management server 1001. According to one embodiment,subsequently, when there is a change in the configuration, such asadding or removing a network access device, changing of subnet settings(for example, by an administrator such as administrators 1007A and 1007Bvia a Web interface of management server 1001), management server 1001generates updated configuration information and communicates the updatesto the network access devices via their corresponding mTunnels (suchcommunication can be done with different mechanisms depending on theembodiment of type of information, including a push mechanism, a pullmechanism, etc.).

A variety of tunneling protocols can be utilized over an mTunnel betweena network access device and management server 1001, such as, forexample, Internet protocol (IP) over user datagram protocol (UDP)(IP/UDP) encapsulation. For example, a network management message may becarried as an IP packet and the IP packet may be encapsulated within aUDP packet exchanged between a network access device and managementserver 1001 over a respective mTunnel. In one embodiment, an IP packethaving one or more network management messages embedded therein may bewrapped with a predetermined mTunnel header and is transmitted within aUDP packet between management server 1001 and a network access device,even if the network access device is behind a NAT device.

In some configurations, if a network access device is behind a firewallthat does not allow any UDP packet going through, a UDP packet carryinga network management message may be encapsulated within a hypertexttransport protocol (HTTP), referred to herein as UDP over HTTP(UDP/HTTP). Since most of the firewalls allow Internet traffic usingHTTP protocol with a transport control protocol (TCP) port of 80, it islikely a UDP packet embedded within an HTTP packet having a destinationTCP port of 80 can reach management server 1001. In such aconfiguration, when management server 1001 receives the HTTP packet, itmay remove any HTTP header to reveal a UDP packet encapsulated therein.Thereafter, an IP packet encapsulated within the UDP packet may beextracted and the network management message within the IP packet can beobtained.

According to one embodiment, management server 1001 and network accessdevices associated with an organization such as network access devices1002 may utilize a private or internal set of IP addresses to exchangenetwork management messages via the respective mTunnel or mTunnels. Thatis, the private IP addresses used by management server 1001 and networkaccess devices 1002 via the respective mTunnel or mTunnels may be in aseparate IP address space (e.g., 6.x.x.x) that is different from an IPaddress space used between network access devices 1002 and their networkclient devices 1008 over LAN(s) 1005 (e.g., 10.x.x.x). That is, theprivate IP addresses described herein are only used between managementserver 1001 and network access devices 1002 to exchange networkmanagement messages over the respective mTunnel(s). In this example,management server 1001 and network access devices 1002 using private IPaddresses to exchange network management messages over mTunnel(s) 1021forms a logical network 1023 (e.g., a logical management network).

Similarly, management server 1001 and network access devices 1003 ofanother organization in this example may utilize a different set ofprivate or internal IP addresses to exchange network management messagesthrough the respective mTunnel or mTunnels, where the private IPaddresses may be in a different IP address space than the one of IPaddresses used between network access devices 1003 and their clientdevices 1009. Similarly, in this example, management server 1001 andnetwork access devices 1003 using private IP addresses to exchangenetwork management messages over mTunnel(s) 1022 forms a logical network1024 (e.g., a logical management network). The private IP addresses(referred to herein as a first set of private IP addresses) used betweenmanagement server 1001 and network access devices 1002 may be differentthan the private IP addresses (referred to herein as a second set ofprivate IP addresses) used between management server 1001 and networkaccess devices 1003. The first and second sets of private IP addressesmay be in different IP address spaces or in the same IP address spacedependent upon the specific configuration.

According to one embodiment, when a network access device is powered upand initialized, the network access device performs certainself-configuration operations to determine whether the network accessdevice should operate as a gateway or as an access point behind agateway. In one embodiment, when a network access device boots up, itinitializes its Ethernet interface and attempts to request an IP address(e.g., a publicly accessible IP address over the Internet, also referredto as an uplink IP address) by broadcasting its media access control(MAC) address within a dynamic host configuration protocol (DHCP)request via its Ethernet interface. If the Ethernet interface of thisnetwork access device is connected to the Internet, a DHCP server, whichmay be a separate server or part of management server 1001, will respondwith a valid IP address assignment, and the network access device willoperate as a gateway device. If there is no DHCP response receivedwithin a predetermined period of time, the network access device assumesthat it is operating behind another gateway device that performs NAT,and the network access device then joins an existing network andoperates as an access point.

According to one embodiment, when operating behind a gateway, each ofthe network access devices derives its own IP address and assigns IPaddresses to its client devices using a predetermined method in aconsistent manner. In one embodiment, a network access device performs ahash operation on at least a portion of its hardware identifier such asa MAC address to generate an IP address. In a particular embodiment, anetwork access device hashes its 6-byte MAC address using apredetermined hash function (e.g., CRC-32 hash function) to generatelower three bytes of its IP address. Note that each of the networkaccess devices may generate two IP addresses for itself: 1) an IPaddress in a first IP address space (e.g., 6.x.x.x) solely forcommunicating network management messages with management server 1001via an mTunnel; and 2) an IP address in a second IP address space (e.g.,10.x.x.x) for normal network traffic with its client devices.

Similarly, when a network client device, such as client devices 1008,requests an IP address, the associated network access device hashes aMAC address of the client device to derive an IP address for the clientdevice. Since each of the network access devices performs the same hashoperation using the same hash function on a MAC address of a clientdevice, the client device can consistently obtain the same IP addressfrom different network access devices. As result, the client device canroam across different network access devices without having to changeits IP address or to perform any address resolution protocol (ARP)related operations.

Referring back to FIG. 7A, as described above, network access devices1002 and network access devices 1003 are associated with differentorganizations and managed by management server 1001. In otherconfigurations, network access devices 1002 and network access devices1003 may be associated with the same organization as shown as system1000B in FIG. 7B. Referring to FIG. 7B, in this configurations, networkaccess devices 1002 and network access devices 1003 may be deployed andlocated at different sites or geographical locations of theorganization. According to one embodiment, at least one virtual privatenetwork (VPN) tunnel 1025 is maintained between at least one of networkaccess devices 1002 and at least one of network access devices 1003,also referred to as a site-to-site VPN. Some or all of the networkaccess devices can be configured, via configuration interface 1014, toparticipate in the site-to-site VPN.

FIG. 8 is a block diagram illustrating a network configuration inaccordance with an embodiment of the invention. Network configuration1100 may be implemented as part of network configurations as shown inFIGS. 7A and 7B. The configuration of NADs 1101 represents one possibleimplementation of one of the LANs 1005 and 1006 of FIGS. 7A-7B, such asthe one including an access network, where one or more of the NADs 1101are in accordance with embodiments of the present invention. That is,any of the routers (e.g., 1102, 1104, 1108 and 1110), network switches(e.g., 1112-1114), and wireless access points (e.g., 1118-1128) shown inFIG. 8 may be implemented by way of the previously described networkaccess devices, including NADs 1002 and 1003 of FIGS. 7A-7B. FIG. 8illustrates the complexity and variety of possible configurations thatmay need to be accounted for by a system administrator (e.g., admin1112) when configuring a network access device within LAN 1104. Forexample, LAN 1104 includes multiple gateways to WAN 1110, multipleVLANs, and multiple possible paths to WAN 1110 by many of the NADs 1101.A change in one of the NADs 1101 may require complex configurationchanges to one or more of the downstream NADs. To be sure, aconfiguration change or fault in wireless access point 1120 may resultin required configuration changes to wireless access points 1122 and1118, and network switches 1112 and 1114. Similarly, a configurationchange or fault in router 1108 may result in required configurationchanges to wireless access points 1126, 1128, and 1124, network switches1116 and 1114, and router 1110. As is apparent, manual configuration ofthe network access devices in a network such as LAN 1104 can be complexand extremely error prone. Furthermore, changes to LAN 1104 resulting ina loss of network connectivity may be difficult to diagnose andtroubleshoot. Accordingly, embodiments of the present disclosure allowfor an installer to install one or more of NADs 1101 by simply poweringon the device and connecting a cable. Then, the NAD may automaticallyestablish a connection to WAN 1110, such that Administrator 1112 mayremotely configure NAD 1102 by way of management server 1114.Furthermore, NADs 1101 may be configured to periodically test theirconnection to WAN 1110 and if it is lost, to automatically establish anew connection to WAN 1110, so as to reduce down time of LAN 1104.

Some portions of the preceding detailed descriptions have been presentedin terms of algorithms and symbolic representations of operations ondata bits within a computer memory. These algorithmic descriptions andrepresentations are the ways used by those skilled in the dataprocessing arts to most effectively convey the substance of their workto others skilled in the art. An algorithm is here, and generally,conceived to be a self-consistent sequence of operations leading to adesired result. The operations are those requiring physicalmanipulations of physical quantities.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise as apparent from the above discussion, itis appreciated that throughout the description, discussions utilizingterms such as those set forth in the claims below, refer to the actionand processes of a computer system, or similar electronic computingdevice, that manipulates and transforms data represented as physical(electronic) quantities within the computer system's registers andmemories into other data similarly represented as physical quantitieswithin the computer system memories or registers or other suchinformation storage, transmission or display devices.

The techniques shown in the figures can be implemented using code anddata stored and executed on one or more electronic devices. Suchelectronic devices store and communicate (internally and/or with otherelectronic devices over a network) code and data using computer-readablemedia, such as non-transitory computer-readable storage media (e.g.,magnetic disks; optical disks; random access memory; read only memory;flash memory devices; phase-change memory) and transitorycomputer-readable transmission media (e.g., electrical, optical,acoustical or other form of propagated signals—such as carrier waves,infrared signals, digital signals).

The processes or methods depicted in the preceding figures may beperformed by processing logic that comprises hardware (e.g. circuitry,dedicated logic, etc.), firmware, software (e.g., embodied on anon-transitory computer readable medium), or a combination of both.Although the processes or methods are described above in terms of somesequential operations, it should be appreciated that some of theoperations described may be performed in a different order. Moreover,some operations may be performed in parallel rather than sequentially.

In the foregoing specification, embodiments of the invention have beendescribed with reference to specific exemplary embodiments thereof. Itwill be evident that various modifications may be made thereto withoutdeparting from the broader spirit and scope of the invention as setforth in the following claims. The specification and drawings are,accordingly, to be regarded in an illustrative sense rather than arestrictive sense.

What is claimed is:
 1. A system comprising: a server comprising: aninterface to allow an administrator to configure access control policies(ACPs) of network client devices (NCDs), a database to store the ACPsreceived from the Web interface; and a plurality of network accessdevices (NADs), communicatively coupled to the server over a network,wherein each NAD of the plurality of NADs is to periodically communicatewith the server to exchange updates of the ACPs between the each NAD andthe server, wherein the each NAD is to enforce the ACPs againstassociated NCDs, and wherein when an NCD of the plurality of NCDsconnects to an NAD of the plurality of NADs and requests to enter a LANassociated with the NAD, the NAD authenticates the NCD and applies arespective ACP of the ACPs to the NCD.
 2. The system of claim 1, whereinthe ACPs comprise one of a bandwidth limit, a traffic shaping rule, avirtual local area network (VLAN) assignment, a firewall rule, or anapplication of a captive portal.
 3. The system of claim 1, wherein thedatabase further stores access control rules (ACRs), each ACR of theACRs specifying on or more ACPs and an expiration time for a specifiedNCD.
 4. The system of claim 3, wherein the specified NCD is identifiedby a media access control (MAC) address
 5. The system of claim 3,wherein the ACRs are stored as a time-ordered log of additions anddeletions of individual rules.
 6. The system of claim 5, wherein theserver periodically re-inserts an old unexpired ACR entry into a frontof the time-ordered log.
 7. The system of claim 1, wherein the each NADis to periodically communicate with the server by sending a version of alast ACP log entry that the each NAD received.
 8. A method comprising:receiving, via a processor at a server, access control policies (ACPs)of network client devices (NCDs); storing the ACPs at the server; andperiodically communicating with a plurality of network access devices(NADs) to exchange updates of the ACPs, the plurality of NADs beingcommunicatively coupled with the server over a network, wherein each NADof the plurality of NADs is to enforce the ACPs against associated NCDs,and wherein when an NCD of the plurality of NCDs connects to an NAD ofthe plurality of NADs and requests to enter a LAN associated with theNAD, the NAD authenticates the NCD and applies a respective ACP of theACPs to the NCD.
 9. The method of claim 8, wherein the ACPs comprise oneof a bandwidth limit, a traffic shaping rule, a virtual local areanetwork (VLAN) assignment, a firewall rule, or an application of acaptive portal.
 10. The method of claim 8, further comprising: storingaccess control rules (ACRs) at the server, each ACR of the ACRsspecifying on or more ACPs and an expiration time for a specified NCD.11. The method of claim 10, wherein the ACRs are stored as atime-ordered log of additions and deletions of individual rules.
 12. Themethod of claim 10, further comprising: periodically re-inserting an oldunexpired ACR entry into a front of the time-ordered log.
 13. The methodof claim 8, wherein the each NAD is to periodically communicate with theserver by sending a version of a last ACP log entry that the each NADreceived.
 14. A non-transitory computer-readable storage device storinginstructions which, when executed by a processor, cause the processor toperform operations comprising: receiving, at a server, access controlpolicies (ACPs) of network client devices (NCDs); storing the ACPs atthe server; and periodically communicating with a plurality of networkaccess devices (NADs) to exchange updates of the ACPs, the plurality ofNADs being communicatively coupled with the server over a network,wherein each NAD of the plurality of NADs is to enforce the ACPs againstassociated NCDs, and wherein when an NCD of the plurality of NCDsconnects to an NAD of the plurality of NADs and requests to enter a LANassociated with the NAD, the NAD authenticates the NCD and applies arespective ACP of the ACPs to the NCD.
 15. The non-transitorycomputer-readable storage device of claim 14, wherein the ACPs compriseone of a bandwidth limit, a traffic shaping rule, a virtual local areanetwork (VLAN) assignment, a firewall rule, or an application of acaptive portal.
 16. The non-transitory computer-readable storage deviceof claim 14, further comprising: storing access control rules (ACRs) atthe server, each ACR of the ACRs specifying on or more ACPs and anexpiration time for a specified NCD.
 17. The non-transitorycomputer-readable storage device of claim 16, wherein the specified NCDis identified by a media access control (MAC) address.
 18. Thenon-transitory computer-readable storage device of claim 16, wherein theACRs are stored as a time-ordered log of additions and deletions ofindividual rules.
 19. The non-transitory computer-readable storagedevice of claim 18, further comprising: periodically re-inserting an oldunexpired ACR entry into a front of the time-ordered log.
 20. Thenon-transitory computer-readable storage device of claim 14, wherein theeach NAD is to periodically communicate with the server by sending aversion of a last ACP log entry that the each NAD received.